<!doctype html>
<html lang="en">

<head>
    <meta charset="utf-8">
    <title>Gradient in HSL space</title>
    <style>
        body {
            background: #fff;
        }

        div {
            width: 300px;
            height: 300px;
            background-image: linear-gradient(in hsl shorter hue 0deg, hsl(0, 100%, 50%) 0%, hsl(120, 100%, 50%) 33.3333%, hsl(240, 100%, 50%) 66.6667%, hsl(0, 100%, 50%) 100%);
        }
    </style>
</head>

<body>
    <div></div>
</body>
</html>
